The ketogenic diet is an accepted alternative for children with intractable generalized or multi-focal seizures not amenable to surgery. It is not commonly used in adults because of the impression that the diet is less effective after childhood, when it is more difficult both to achieve ketosis and to change dietary habits. We present a 20-year-old man with intractable epilepsy since early childhood who is being treated with great success by a medium-chain triglyceride ketogenic diet. It has not only controlled the seizures but has also improved quality of life. We recommend a therapeutic trial of the ketogenic diet in intractable epilepsy for all ages.